Improvements in and relating to an apparatus for adjusting a fluid throughput

ABSTRACT

The valve provides an unrestricted flow through a chamber from a first opening to a second opening while the reverse flow is first adjusted to a fine extent so as to allow a gradual increase in flow until full throughput is reached. To this end a large primary closing member engages the first opening so as to be urged off its seat under the action of the fluid entering said opening whereas the opposite flow seats said primary closing member. For this opposite flow, a control member causes a secondary closing member constituted by a rod coaxial with the primary control member to recede out of a port formed in the primary member. When said rod has receded sufficiently and allowed a sufficient throughput, it draws along with it the primary closing member which leads to the desired full throughput in said opposite direction.

United States Patent l37/630.15 X 137/512.1 X 137/630.l5 X 137/599 X mom"L mmm B m dmu a Il CWKS 9250 .4667 9999 1111 ///l 7502 7397 36 0 1 72 573 9 .3 2333 d n h Hr m i 9 m. S ws! V ae v a n4 e m G8 0 rl m d v mm mAF U N 7 22 Patented Sept. 7, 1971 FOREIGN PATENTS 18 93GreatBritain................

[73] Assignee LuciierS. A.

Primary Examiner-Laverne D. Geiger Assistant Examiner-David J. ZobkiwCarouge-Geneva, Switzerland [32] Priority Oct.3l, 1969 [3 3] Switzerland[31 16272/68 Attorneys-Emory L. Groff and Emory L. Groff, Jr.

54] APPARATUS FOR ADJUSTING A FLUID ABSTRACT: The valve provides anunrestricted flow through THROUGHPUT a chamber from a first opening to asecond opening while the reverse flow is first adjusted to a fine extentso as to allow a 3 Chums 2 Drawmg Figs gradual increase in flow untilfull throughput is reached. To this end a large primary closing memberengages the first opening so as to be urged off its seat under theaction of the fluid entering said opening whereas the opposite flowseats said primary closing member. For this opposite flow, a controladmin 1 9 0540 3.13 6 6 W/k3 76 1 9 J 5 m9 m m3 R m m .1 m m m m m WW Im m mm H "9 n "4 L T C 10 s y U IF l. 1.] 2 0 5 55 .l .121.

member causes a secondary closing member constituted by a rod coaxialwith the primary control member to recede out of [56] References CitedUNITED STATES PATENTS 4/1889 Foster...................,......

a port formed in the primary member. When said rod has recededsufficiently and allowed a sufficient throughput, it

401,647 137/630.15 draws along with it the primary closing member whichleads to 2,089,419 8/1937 Peo et a1. 137/513.3 X the desired fullthroughput in said opposite direction.

PATENTEUSEP H9?! 3.603 344 sum E 0F 2 Fig.2

INVENTOR fihmm STAMPFL/ ATTORNEY APPARATUS FOR ADJUSTING A FLUIDTHROUGHPUT The present invention has for its object an apparatus adaptedto ensure a fine adjustment of a fluid output, more particularly anadjustment of the throughput for one direction of flow while the flow inthe opposite direction remains unrestricted.

ln control systems incorporating pneumatic jacks it is often ofadvantage to provide a possibility of adjustment for the jack pistonswith a view to producing a high speed progression in one direction and aslower return movement. Several adjusting means are known which includea closing member the position of which may be adjusted by means of ascrew for instance. Such known arrangements all have however thedrawback of making a fine adjustment a difficult matter, since even avery small shifting of the closing member leads for a given crosssection afforded to a considerable modification of the throughput.

The present invention has for its object elimination of said difficultyand it is directed to an apparatus for adjusting a fluid throughput, ofthe type including a chamber provided with two openings for the passageof the fluid, a first closing member adapted to slide axially withinsaid chamber between a closing and an opening position while a secondclosing member is adapted to be shifted axially by a control member withreference to a port provided for the fine adjustment of the fluidthroughput. Now according to the invention, the two closing members arecoaxial and have different cross sections, the port provided for thefine adjustment of the fluid throughput being formed through the wall ofthe first closing member.

In the accompanying drawings illustrating diagrammatically an embodimentof the invention:

FIG. 1 is a longitudinal sectional view of said embodiment;

FIG. 2 is a graph illustrating the flow of fluid through the apparatus.

Said apparatus comprises as illustrated a body 1 enclosing a cylindricalchamber 2 provided with two ports 3 and 4. A bellshaped, first closingmember 5 made of plastic material is slidingly carried inside saidchamber so as to be capable of moving axially therein towards and awayfrom the opening 3. The upper section 6 of the closing member 5 isadapted to engage fluidtightly a seat formed by the shoulder 7 at theentrance of the opening 3 when the closing member is in its operativeclosing position illustrated in FIG. 1. The skirt of the closing member5 is providedwith longitudinal slots such as 8 which afford a permanentcommunication between the inside of the closing member 5 and the lateralopening 4 of the chamber 2 whatever may be the axial position of saidclosing member inside the latter. At its upper end the closing member 5shows a port 9 through which a fine adjustment of the throughput may beobtained and the part played by which will be disclosed hereinafter withfurther detail. Said port 9 affords a communication between the opening3 of the chamber 2 and the inside of the closing member 5 and thereforebetween said opening 3 and the lateral opening 4 of said chamber.

At its end facing away from the opening 3 and coaxially therewith, thebody 1 is tapped as shown at 10 so as to be engaged by the threads 11 onone end of a cylindrical section 13 which is disposed with a slightfriction fit inside the chamber 2. Said cylindrical section 13 isprovided on its outer surface with an annular groove 14 inside which isfitted a fluidtight toreshaped packing 15. A rod 16 coaxially rigid withthe cylindrical section 13 may engage, with a slight amount of friction,the port 9 in the closing member 5 to thus provide a second closingmember.

The cylindrical section 13 further includes a tubular extension 17 atits end facing the closing member, said extension being coaxial with therod 16. The outer end of said tubular extension is provided with anouter shoulder 18 adapted to engage an inner flange 19 at thecorresponding end of the closing member 5. The latter is rigid with aninner central tubular extension 12 adapted to guide a coil spring 20fitted in a compressed condition between the upper inner surface oftheclosing member 5 and the bottom of the tubular extension 17 of the screw11.

The operation of the apparatus is as follows:

When in the position illustrated, the closing member 5 is held incontact with the seat 7 surrounding the opening 3 by the compressedspring 20.

lfcompressed fluid is fed through the opening 3, its pressure urges thefirst closing member 5 against the comparatively weak pressure exertedby the spring 20 so that the fluid can flow freely from the inputopening 3 towards the output opening 4. it should be noted that the rod16 does not oppose the shifting of the closing member 5 towards itsopening position since it can engage with a slight amount of frictionthe port 9 in the upper end of the closing member 5.

In the case of a reversal in the direction of flow of the fluid, that isif the compressed fluid enters through the opening 4, said fluid flowsinto the inside of the skirt of the closing member 5 through the slots8. Under the action of the pressure exerted against its inner wall, theclosing member 5 is urged against its seat 7 surrounding the opening 3so that a fluidtight contact is obtained between the upper section 6 ofthe closing member 5 and the seat 7.

If the rod l6 occupies the position illustrated in FIG. I. the fluid mayescape from the inside of the closing member 5 towards the opening 3through said port 9. Upon screwing of the screw 11, the latter is causedto progress within the chamber 2 so as to gradually reduce the crosssection afforded for the passage of the fluid through the port 9, theflow of fluid being arrested when the rod 16 closes completely the port9. At such a moment, the passage of fluid out of the opening 4 towardsthe opening 3 is completely cutoff. The graph of FIG. 2 illustrates thevariations of the fluid throughput through the free cross section in thedirection from B towards A that is from the opening 4 towards theopening 3, said graph carrying in ordinates the throughput Q and inabscissae the shifting C of the screw 11, the graph being drawn. for anunvarying drop in pressure in the adjusting apparatus.

If the screw 11 is unscrewed, the rod 16 gradually uncovers the port 9.Since the cross section of said port 9 is very small with reference tothe cross section of the opening 3, it is obvious that the axialshifting of the rod 16 with reference to the port 9 allows a very fineadjustment of the throughput of fluid flowing from the opening 4 towardsthe opening 3, this being illustrated in FIG. 2 by the section a of thecurve for which section a shifting a of the screw 11 carrying along withit the rod 16 is proportional to the throughput Q.

When the rod 16 has moved sufficiently far from the opening port 9 so asto release entirely the cross section of said port 9, the shoulder 18 onthe tubular extension 17 of the screw It draws along with it the closingmember 5 by engaging the inner flange 19. Consequently, any furtherrotary movement of the screw 11 in the same direction results in agradual shifting of the closing member 5 away from the shoulder 7surrounding the opening 3. The increase in fluid throughput for eachfraction of a revolution of the screw 11 is then much larger than whenthe throughput is adjusted solely by the rod 16 cooperating with theport 9 so as to ensure a fine adjustment of said throughput. This isshown on the graph of PK]. 2 by a sudden increase in the throughput asillustrated by the section b of the curve for a shifting b of the screw11.

I claim:

1. An apparatus for adjusting a fluid throughput comprising a bodyenclosing a chamber provided with a first opening and with a secondopening, a first closing member adapted to slide inside the chamberbetween an operative position closing the first opening and aninoperative position uncovering said first opening, said first closingmember being provided with a port facing said first opening, a secondclosing member the diameter of which is smaller than that of the firstclosing member, said second closing member comprising a cylindrical rodslidable coaxially within the first closing member in axial registrywith the port in said first closing member between an operative positionin which it slidably and frictionally engages said port and aninoperative position out of engagement with said port permitting anadjustably reduced flow of fluid out of the second opening through saidport towards the first opening, the locationof said rod relative to saidport defining the flow of fluid through said port, means controlling theposition of the first and second closing members, said means controllingthe position of the first and second closing members controlling theposition of said second member independent of fluid conditions in saidapparatus, said first closing member being substantially bell-shaped incross section, the convex portion thereof facing said first opening andmovable into its operative closing position by biasing means and by thepressure of fluid entering said chamber through said second opening andimpinging on the concave surface of the bell-shaped member and urgedaway from its closing position and toward said second closing member bythe fluid entering the first opening, the movements of said firstclosing member under the action of the fluid entering either of saidopenings being independent of the movements of said second closingmember.

2. An apparatus as claimed in claim I, wherein the means controlling theposition of said first and second closing members includes a memberthreadedly engaging the body and coaxially rigid with said secondclosing member, the rotation of said threadedly engaging member definingthe axial shifting of the second closing member with reference to theport in the first closing member.

3. An apparatus as claimed in claim 2, wherein said threadedly engagedmember includes abutting means engaging the first closing member forshifting it into an open position when the second closing member'hasbeen moved over a predetermined value thereby controlling the positionof said first closing member.

1. An apparatus for adjusting a fluid throughput comprising a bodyenclosing a chamber provided with a first opening and with a secondopening, a first closing member adapted to slide inside the chamberbetween an operative position closing the first opening and aninoperative position uncovering said first opening, said first closingmember being provided with a port facing said first opening, a secondclosing member the diameter of which is smaller than that of the firstclosing member, said second closing member comprising a cylindrical rodslidable coaxially within the first closing member in axial registrywith the port in said first closing member between an operative positionin which it slidably and frictionally engages said port and aninoperative position out of engagement with said port permitting anadjustably reduced flow of fluid out of the second opening through saidport towards the first opening, the location of said rod relative tosaid port defining the flow of fluid through said port, meanscontrolling the position of the first and second closing members, saidmeans controlling the position of the first and second closing memberscontrolling the position of said second member independent of fluidconditions in said apparatus, said first closing member beingsubstantially bellshaped in cross section, the convex portion thereoffacing said first opening and movable into its operative closingposition by biasing means and by the pressure of fluid entering saidchamber through said second opening and impinging on the concave surfaceof the bell-shaped member and urged away from its closing position andtoward said second closing member by the fluid entering the firstopening, the movements of said first closing member under the action ofthe fluid entering either of said openings being independent of themovements of said second closing member.
 2. An apparatus as claimed inclaim 1, wherein the means controlling the position of said first andsecond closing members includes a member threadedly engaging the bodyand coaxially rigid with said second closing member, the rotation ofsaid threadedly engaging member defining the axial shifting of thesecond closing member with reference to the port in the first closingmember.
 3. An apparatus as claimed in claim 2, wherein said threadedlyengaged member includes abutting means engaging the first closing memberfor shifting it into an open position when the second closing member hasbeen moved over a predetermined value thereby controlling the positionof said first closing member.